Conventional printing apparatuses include, for example, a thermal printer equipped with a thermal head which has a plurality of heating elements arranged in the width direction of paper to be printed on. The thermal printer is generally driven by electric power of a battery. The thermal head is replaceable and detachable from the main body of the thermal printer.
Jpn. Pat. Appln. KOKAI Publication No. 2007-30263 describes the configuration of a thermal printer, wherein when printing is performed, heating elements corresponding to printing parts are heated among a plurality of heating elements to enable printing of various kinds of information.
Jpn. Pat. Appln. KOKAI Publication No. 11-78083 describes the configuration of a printer having an intermediate substrate, wherein an intermediate connector having a connecting structure adapted to a head connector can be selected from a plurality of kinds of intermediate connectors and connected to the intermediate substrate so that thermal heads different in the kind of dot density can be exchanged.
In the thermal printer described in Jpn. Pat. Appln. KOKAI Publication No. 2007-30263, a platen roller provided opposite to a thermal head is moved step by step by a pulse motor to carry paper to the position where thermal head is located. The thermal head performs printing for one line in accordance with a one-step operation of the pulse motor.
There are a plurality of standards for thermal heads used in the thermal printers, such as a thermal head having a resolution of 203 dpi or a thermal head having a resolution of 300 dpi. The length of one side of one dot in the case of the thermal head of 203 dpi is different from that in the case of the thermal head of 300 dpi. However, the carrying distance for the one-step operation of the pulse motor is fixed unless a mechanical modification is made. Therefore, for example, when the head having a resolution of 203 dpi is mounted on a thermal printer equipped with a mechanism adapted to the head having a resolution of 300 dpi, the problem is that the longitudinal and lateral lengths of a printed dot are different from each other.
In order to adapt the mechanism to each head, a plurality of kinds of mechanisms have to be attached. In this case, the problem is that the apparatus is increased in size and cost is increased.
Furthermore, Jpn. Pat. Appln. KOKAI Publication No. 11-78083 shows that a plurality of kinds of thermal heads are exchanged in the thermal printer, but does not describe any configuration for identifying the kind of attached thermal head.
It is therefore an object of the present invention to provide a printing apparatus which can adapt to a plurality of kinds of heads.